Duplex Scale Tuning

[Doug Hershberger]

Del & list,
    This is an interesting subject and thank you for educating us Del. If
what Del is saying about duplexes is true and I believe it is, it reminds me
of what I heard was common practice among manufacturers of all kinds of
products. If you can't fix it, feature it. Thus the marketing angle.
   I tuned a 1915 Bosendorfer the other day and it did not have a duplex
scale. It was in original condition and sounded wonderful including that
killer octave range. It was obvious from looking this piano over that it had
to have been from a golden age of piano making.
   What was Steinway's role in developing the duplex scale? I'm sure to some
folks in those earlier days the Steinways, which I believe were continually
getting louder and brasher sounding were too much. A technician friend of
mine was reading something about the early days of Steinway and the author
was speculating that alot of people in the factory in those days could have
actually had major hearing loss. I guess we were just talking about why
Steinway started using hammer hardners. If there is any truth to that maybe
it could apply to the duplex scale as well. Of course there is no way to
prove that but when he told me it made me wonder. It might have been from
the man that tranlated Helmholtz's book.  Sorry I cannot remember the
source. I'll ask next time I see him.
Doug Hershberger,RPT
Aliso Viejo, CA
----- Original Message -----
From: Delwin D Fandrich <pianobuilders@olynet.com>
To: <pianotech@ptg.org>
Sent: Tuesday, December 21, 1999 10:21 PM
Subject: Re: Duplex Scale Tuning


>
> ----- Original Message -----
> From: <ETomlinCF3@AOL.COM>
> To: <pianotech@ptg.org>
> Sent: Tuesday, December 21, 1999 3:44 PM
> Subject: Re: Duplex Scale Tuning
>
>
> > What a load.  Take a piano with a good duplex and play it with and
without
> > the duplex muted and the difference is very noticeable.  How can one say
> that
> > it is a marketing plan?  Lost energy ... we even see energy transferring
> into
> > the plate and almost all other components.
> >
> > Ed Tomlinson
> >
> -----------------------------------------------------------
>
> That rather depends on what is used to mute the tuned duplex and how the
> muting is done.  If something soft -- like a loose felt strip -- is used,
> yes, there will be losses.  With the standard "tuned duplex" design there
is
> quite a lot of energy transferred to the string segment between the V-bar
> and the counterbearing bar.  Some of this energy is ultimately fed back to
> the normal speaking portion of the string, but the rest of it is
dissipated
> into the plate and is absorbed as heat.  When felt is used to mute out
this
> segment it acts just like a damper so there will be a loss of sustain.
> Sometimes this loss is significant.
>
> If, however, the muting is done with something rigid -- like a brass rod,
or
> bar -- then, no, there will be no discernable losses and the string
> termination will be improved.  Even better, if the string deflection angle
> can be increased and/or the length of the duplex segment made shorter --
it
> is now no longer "tuned" and it is no longer vibrating significantly --
then
> string termination will be improved and sustain will not be adversely
> effected.  Indeed, it may well be improved.
>
> Del
>